Multicast mapped look-up on content delivery networks

ABSTRACT

A method and system for flexibly processing content objects is disclosed. A content object is stored on one of a plurality of storage devices. A request is received for the content object. Information corresponding to the requested object (e.g., a unique identifier) is transmitted to one or more content directories. A response is received from a first content directory indicating a location of the content object. The content object is requested from the first location, and at least part of the content object is received.

This application is related by priority to: PCT/US11/023410 filed Feb.1, 2011, entitled “Asset Management Architecture for Content DeliveryNetworks,” and Australian Patent Application No. 2011203266 filed Feb.1, 2011, entitled “Multicast Mapped Look-Up On Content DeliveryNetworks;” both of which are hereby incorporated by reference in theirentirety for all purposes.

BACKGROUND

This disclosure relates in general to content delivery networks (CDNs)and, but not by way of limitation, to managing assets associated withthe CDN.

Content providers (i.e., customers) offload their content delivery toCDNs for any number of reasons. CDNs specialize in a range of contentdelivery and hosting options optimized for performance so that end usersget a desired quality of service (QoS). Different CDNs have differenttopologies relying on more or less points of presence (POPs) distributedgeographically across the Internet. CDNs with more POPs tend to haveless resources in each POP, while those with less POPs tend to have moreresources in each one. The topology and asset allocation in a particularCDN is inflexible.

Customers are using CDNs and cloud services in more creative ways.Applications, storage and other services are being provided remotely.CDNs have not provided the flexibility to adapt to all the needs ofcustomers yet have an excellent topology of distributed POPs with fastinterconnectivity between those POPs. Currently, limited interfaces tothe CDN with little or no customization results in lost opportunity.

SUMMARY

In one embodiment, the present disclosure provides a method and systemfor flexibly processing content objects. The processing is performedwith a content delivery network (CDN) having a number of geographicallydistributed points of presence (POPs). Content objects are ingestedthrough landing pads and stored or otherwise processed in a flexible waywhere storage bricks and other resources are chosen flexibly bycharacterization tags. Policies are used to describe which contentobjects are processed by which categories of resources. A group ofresources characterized by the tag are chosen when the processing isperformed. When retrieving content, the content object can be stored onany storage brick found through the tag analysis process. A query istranslated to addresses for the chosen storage brick(s).

In another embodiment, the present disclosure provides a method forsourcing a content object from a content delivery network (CDN) having aplurality of points of presence (POPs) distributed geographically. Thecontent object is received for storage on the CDN. A unique identifierfor the content object is identified to distinguish it from othercontent objects in the CDN. The content object is stored on a storagedevice chosen from a plurality of storage devices. A uniform resourcelocator (URL) is received for the content object indicating a file nameand a path from an end user system at a POP of the plurality of POPs.Information corresponding to the file name and the path is multicast toa plurality of content directories distributed geographically within theCDN. Each content directory can provide location information for any ofthe plurality of storage devices that store at least some of the contentobject. A response is received from a content directory including afirst location of the storage device and the unique identifier. Theunique identifier is requested from the first location. At least some ofthe content object is passed from the first location to a secondlocation within the CDN. At least some of the content object is returnedto the end user system from the CDN.

In another embodiment, the present disclosure provides a contentdelivery network (CDN) for storing content objects and deliveringcontent objects over a network to a user computer. The CDN includes aswitching fabric to receive and route requests for content objects fromuser computers to a particular edge server, the requests including afilename. The CDN also includes a plurality of points of presence (POPs)distributed geographically. Each POP includes a metadata directoryincluding a unique identifier assigner for assigning a unique identifierto a new content object; a content mapper coupled to a plurality oflookup listeners; and an edge server coupled to the switching fabric andto the content mapper. The edge server is configured to receive arequest for a content object from the switching fabric, the requestincluding a file name and/or a path of the requested content object. Thecontent mapper is configured to receive the file name and/or the pathfrom the edge server; translate the file name and/or the path into acorresponding unique identifier; transmit, at least partiallysimultaneously, the corresponding unique identifier to each of thelookup listeners; receive information identifying a location of astorage device storing the requested content object from one or more ofthe lookup listeners; and request the requested content object from thelocation.

In another embodiment, the present disclosure provides a method forsourcing a content object from a content delivery network (CDN) having aplurality of points of presence (POPs) distributed geographically. Thecontent object for storage is received on the CDN. A unique identifierfor the content object is determined to distinguish it from othercontent objects in the CDN. The content object is stored on a storagedevice chosen from a plurality of storage devices. A uniform resourcelocator (URL) is received for the content object indicating a file nameand a path from an end user system at a POP of the plurality of POPs.Information corresponding to the file name and the path is multicast toa plurality of content directories distributed geographically within theCDN, wherein each content directory can provide location information forany of the plurality of storage devices that store at least some of thecontent object. A response is received from a content directoryincluding a first location of the storage device and the uniqueidentifier. The unique identifier is requested from the first location.At least some of the content object is returned from the first locationto a second location within the CDN. At least some of the content objectis returned to the end user system from the CDN.

In another embodiment, the present disclosure provides a contentdelivery network (CDN) having a plurality of points of presence (POPs)distributed geographically for sourcing a content object. The CDNincludes two or more hardware servers programmed for: receiving thecontent object for storage on the CDN; determining a unique identifierfor the content object to distinguish it from other content objects inthe CDN; storing the content object on a storage device chosen from aplurality of storage devices; receiving a uniform resource locator (URL)for the content object indicating a file name and path from an end usersystem at a POP of the plurality of POPs; multicasting informationcorresponding to the file name and a path to a plurality of contentdirectories distributed geographically within the CDN, wherein eachcontent directory can provide location information for any of theplurality of storage devices that store at least some of the contentobject; receiving a response from a content directory including a firstlocation of the storage device and the unique identifier; requesting theunique identifier from the first location; returning at least some ofthe content object from the first location to a second location withinthe CDN; and returning at least some of the content object to the enduser system from the CDN.

In another embodiment, the present disclosure provides a method forsourcing a content object from a content delivery network (CDN) having aplurality of points of presence (POPs) distributed geographically. Thecontent object is received for storage on the CDN. The content object isassociated with an identifier to distinguish it from other contentobjects in the CDN. The content object is stored on a storage devicechosen from a plurality of storage devices. A first request for thecontent object is received from an end user system at a POP of theplurality of POPs. Information about the requested content object istransmitted, at least partially simultaneously, to a plurality ofcontent directories distributed geographically within the CDN. Aresponse is received from a first content directory indicating that thecontent object is stored at a first location, the first location being alocation of the storage device. A second request for the content objectis transmitted to the first location. At least some of the contentobject is received at a second location within the CDN from the firstlocation, the second location being different from the first location.At least some of the content object is returned to the end user systemfrom the CDN.

In another embodiment, the present disclosure provides a contentdelivery network (CDN) having a plurality of points of presence (POPs)distributed geographically for sourcing a content object. The CDNincludes a mapper transport for: receiving a request for a content file;and transmitting, at least partially simultaneously, multiple andidentical requests for information about a location of the content file.The CDN also includes a first of a plurality of content directoriesprogrammed for: receiving one of the location requests; querying amapper cabinet that associates content files with storage addresses; andtransmitting information identifying a storage location of the contentfile to the mapper transport.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating various embodiments, are intended for purposes ofillustration only and are not intended to necessarily limit the scope ofthe disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is described in conjunction with the appendedfigures:

FIG. 1 depicts a block diagram of an embodiment of a contentdistribution system;

FIGS. 2A and 2B depict block diagrams of embodiments of a point ofpresence (POP);

FIGS. 3A and 3B depict block diagrams of embodiments of a contentmanagement architecture;

FIGS. 4A and 4B depict block diagrams of embodiment of a content brickor resource;

FIG. 5 depicts a block diagram of an embodiment of the policyreconciliation service interacting with a metadata directory;

FIG. 6 depicts a diagram of an embodiment of a directory structure;

FIGS. 7 and 8 illustrate swim diagrams of embodiments of a process forusing the content management architecture to retrieve a content object;

FIG. 9 illustrates a flowchart of an embodiment of a process forapplying policies to a content object;

FIG. 10 illustrates a flowchart of an embodiment of a process forconfiguring a customer account;

FIG. 11 illustrates a flowchart of an embodiment of a process fordisambiguation of policies;

FIGS. 12A, 12B and 12C depict block diagrams of embodiments of policyprioritization hierarchies;

FIG. 13 illustrates a flowchart of an embodiment of a process forperforming a policy;

FIG. 14 illustrates a flowchart of an embodiment of a process forenrolling a resource or brick into the content distribution system;

FIG. 15 illustrates a flowchart of an embodiment of a process fordelivering a content object using the content management architecture;

FIGS. 16A and 16B illustrate flowcharts of embodiments of a process forelastically managing propagation of content objects; and

FIG. 17 illustrates a flowchart of an embodiment of a process for usingpolicies to change the jurisdiction used to process a content object.

In the appended figures, similar components and/or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If only the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

DETAILED DESCRIPTION

The ensuing description provides preferred exemplary embodiment(s) only,and is not intended to limit the scope, applicability or configurationof the disclosure. Rather, the ensuing description of the preferredexemplary embodiment(s) will provide those skilled in the art with anenabling description for implementing a preferred exemplary embodiment.It is understood that various changes may be made in the function andarrangement of elements without departing from the spirit and scope asset forth in the appended claims.

Referring first to FIG. 1, a block diagram of an embodiment of a contentdistribution system 100 is shown. The content originator 106 offloadsdelivery of the content objects to a content delivery network (CDN) 110in this embodiment. The content originator 106 produces and/ordistributes content objects and includes a content provider 108, acontent site 116, and an origin server 112. The CDN 110 can cache,redistribute and/or host content in various embodiments for thirdparties such as the content originator 106 to offload delivery andtypically provide better quality of service (QoS).

In this embodiment, the content distribution system 100 locates thecontent objects (or portions thereof) and distributes the contentobjects to end user systems 102. A content object is any content file orcontent stream and could include, for example, video, pictures, data,audio, software, and/or text. The content object could be live, delayedor stored. Throughout the specification, references may be made to acontent object, content, content stream and/or content file, but it isto be understood that those terms could be used interchangeably whereverthey may appear.

Many content providers 108 use a CDN 110 to deliver the content objectsover the Internet 104 to end users 128. The CDN 110 includes a number ofpoints of presence (POPs) 120, which are geographically distributedthrough the content distribution system 100 to deliver content. Variousembodiments may have any number of POPs 120 within the CDN 110 that aregenerally distributed in various locations around the Internet 104 to beproximate to end user systems 102. Multiple POPs 120 use the same IPaddress such that an Anycast routing scheme is used to find a POP 120likely to be close, in network terms, to the end user for each request.In addition to the Internet 104, a wide area network (WAN) 114 or otherbackbone may couple the POPs 120 with each other and also couple thePOPs 120 with other parts of the CDN 110.

When an end user 128 requests a web page through its respective end usersystem 102, the request for the web page is passed either directly orindirectly via the Internet 104 to the content originator 106. Thecontent originator 106 is the source or re-distributor of contentobjects. The content site 116 is a web site accessible by the end usersystem 102. In one embodiment, the content site 116 could be a web sitewhere the content is viewable with a web browser. In other embodiments,the content site 116 could be accessible with application software otherthan a web browser. In this embodiment, the content provider 108 directscontent requests to a CDN 110 after they are made or formulates thedelivery path to the CDN 110 by embedding the delivery path into theURLs for a web page. In any event, the request for content is handedover to the CDN 110 by using an Anycast IP address corresponding to one,two or more POPs 120.

Once the request for a content object is passed to the CDN 110, therequest is associated with a particular POP 120 within the CDN 110 usingthe Anycast routing scheme. The particular POP 120 may retrieve contentobject from the content provider 108 if not already within the CDN 110.Alternatively, the content provider 108 may directly provide the contentobject to the CDN 110 and its associated POPs 120 through pre-populationor hosting in advance of the first request. The CDN servers include edgeservers that actually serve end user requests. The origin server 112holds a copy of each content object for the content originator 106.Periodically, the content of the origin server 112 may be reconciledwith the CDN 110 through a cache, hosting and/or pre-populationalgorithm. Some content providers 108 could use an origin server withinthe CDN 110 to host the content and avoid the need to maintain anaccessible copy of the content object at the origin server 112 of thecontent originator 106.

Once the content object is retrieved from the origin server 112 by theCDN 110, the content object is stored in a manner accessible to the CDNto allow processing by that POP 120 to service the end user systems 102.For example, the content object could be stored on a brick 130. Streamedcontent objects can have real time or near real time information or canbe previously stored. The end user system 102 receives the contentobject and processes it for use by the end user 128. The end user system102 could be a personal computer, media player, handheld computer,Internet appliance, phone, IPTV set top, web server, processing system,streaming radio or any other device that receives and/or plays contentobjects. In some embodiments, a number of the end user systems 102 couldbe networked together. Although this embodiment only shows a singlecontent originator 106 and a single CDN 110, it is to be understood thatthere could be many of each in various embodiments.

Storage accessible to the CDN 110 includes bricks 130 in thisembodiment. A brick 130 is any storage medium inside or outside the CDN110 that is part of a content management architecture (CMA). The storagemedium includes a layer of software to accommodate commands for thebrick. Any storage array, network attached storage, drive, flash media,or other non-volatile memory could act as a brick 130 with the properlayer of software. In this embodiment, one of the end user systems 102-1has a brick 130-1 coupled to it. The CDN 110 could store content on anybrick 130 to implement a policy, regardless of whether the brick isinternal or external to the CDN 110.

Other resources 134 are available to the CDN 110 to process content.Resources 134 can be internal or external to the CDN 110. A brick 130 isjust a resource, but it is broken out separately since the processing itperforms is largely limited to storage. Generally, a resource 134 is anyhardware or software function that can store or process a contentobject. Examples include, transcoders, cryptographic processors,compression engines, content processors (e.g., image processors, videoprocessors or audio processors), thumbnail generators, media syndicationservices, video/audio ad insertion engines, video processing services,metadata insertion engines, or anything that can process content objectsand can be interfaced with an API from the CDN 110. In this example,there is a first resource 134-1 available to the CDN 110 over theInternet 104 and a second resource 134-2 within the CDN 110, but it isto be understood there could be many more resources available to the CDN110.

With reference to FIG. 2A, a block diagram of an embodiment of a POP120-1 is shown. There are both legacy edge servers 235 that don'tnatively support the CMA and edge servers 230 that do in thisembodiment. Legacy edge servers 235 use a mapper transport 245 thatsupports the CMA to gather any content requested from CDN 110 andpresent the content like an origin server. The mapper transport 245makes the calls necessary to locate the content and pass it to thelegacy edge server 235. Requests are made to bricks 130 by the mappertransport 245 that acts as a reverse proxy to return the requestedcontent. Typically, the software on the legacy edge server 235 does notrequire any rewriting to allow integration with the CMA because of themapper transport 245.

The various edge servers 230, 235 are coupled to each other and theInternet 104 and WAN 114 using switching fabric 240. Edge servers 230,235 number in the thousands in a given POP 120. The edge servers 230,235 could be divided by function and/or customer. Loading algorithms canbe used to divide load among the edge servers 230, 235 in any number ofways. The edge servers 230 perform caching, streaming, hosting, storage,and/or other functions within the POP 120. An edge server 230, 235 istypically a rack-mounted computer that could have varying levels ofprocessing power, memory and storage. Software running on the edgeserver 230, 235 includes, for example, HTTP proxy caching, mediaservers, Flash™ servers, Java™ application servers, Silverlight™servers, etc.

The switching fabric 240 is used for several functions. Incomingrequests for content objects are routed to the edge servers 230, 235using the switching fabric. This could be done using routing,redirection or domain name service (DNS). Load balancing, round-robin,and/or other techniques could be used by the switching fabric 240 toroute requests to edge servers 230, 235. Communication within the POP120 also uses the switching fabric 240. Edge servers 230, 235 could havemultiple software applications running that communicate with other edgeservers 230, 235.

There are legacy landing pads 215 and landing pads 210 supporting CMA.The legacy landing pads 215 use a legacy adapter 285 to integrate withthe CMA. The legacy adapter 285 includes a portable operating systeminterface for Unix (“POSIX”) adapter to allow backward compatibility tolegacy landing pads 215. Many applications are designed to directlyinterface with the AMA without requiring the POSIX functionality of thelegacy adapter 285. A universal namespace and directory space isprovided by the legacy adapter 285 for the CMA to abstract the legacystorage interface from the native storage. There can be multiple landingpads 210, 215 in multiple POPs 120 for a given customer to provide aningest point for content objects.

A content directory 205 is provided for the CMA to allow locating,processing and storing content. The content directory 205 includes ametadata directory 275 and a content mapper 220. The metadata directory275 manages through selection of resources and bricks that are membersof tag and tagset groups, which resources and bricks are selected forparticular processing task. The content mapper 220 is just a databasestoring UUID and corresponding path and filename along with the brickaddresses that store the file referenced by a particular UUID. Thehealth of bricks 130 and resources 134, metadata, tags, and otherinformation is maintained by the metadata directory 275. All bricks 130and resources 134 have various tags associate with them. For each tag ortagset, the bricks 130 or resources 134 that have that tag or tagset areknown to the metadata directory 275 to allow selection of a brick 130 orresource 134 for a particular processing task performed on a contentobject.

The content mapper 220 is a distributed database or data structure thattranslates path and filename to a universal unique identifier (UUID). Inthis embodiment, the UUID is a 256-bit number that is randomly,pseudorandomly, sequentially, or unpredictably assigned to each contentobject file stored in the CDN 110. It is extremely unlikely that twofiles would have the same UUID and a check could be performed prior toassignment to be sure the UUID generated hasn't already been used withinthe CDN 110.

A policy reconciliation service (PRS) 260 maintains and processespolicies. Each policy defines processing to perform on one or morecontent objects. The operation of a policy is affected by criteria basedupon metadata and tags/tagsets. Where there are multiple policiesapplicable to content, the PRS disambiguates the situation based upon ahierarchy or by picking the lowest or highest common denominator for theapplicable policies.

Within each POP 120 or elsewhere in the CDN, there are a number ofbricks 130 that store content objects and resources 134 that process thecontent objects. A policy can define the classes of bricks suitable forstorage and the processing that a resource 134 would perform on acontent object. Parameters are passed to a resource 134 using a mutatorthat is part of a policy.

With reference to FIG. 2B, a block diagram of an embodiment of a POP120-2 is shown. The edge servers 230 and landing pads 210 in thisembodiment natively support the CMA without any translation orinterfaces required. Calls are made to the content directory 205 to findthe UUID for a content object and the brick names or identifiers thathold the content object. When storing content objects, the contentdirectory 205 uses the tags and metadata to choose one or more bricks130 that would store a particular content object.

With reference to FIG. 3A, a block diagram of an embodiment that showsportions of a content management architecture (CMA) using legacy edgeservers 235. This embodiment has only legacy edge hosts 316 and legacyedge caches 304 instantiated on the legacy edge servers 235. Otherembodiments could additionally include edge caches and/or edge serversthat natively support the CMA.

When a content object or portion thereof is not found on the legacy edgeserver 235, reference to a mapper transport 245 is made. The mappertransport 245 acts as an origin server for all the content in the CMA.The mapper transport 245 interacts with the lookup listeners 328 to getnames or addresses of the bricks 130 that hold the content object alongwith its UUID. The mapper transport 245 then proxies the content objectback to the requesting legacy edge cache 304 or legacy edge host 316.The protocol and handshaking expected by the legacy edge cache 304 orlegacy edge host 316 is performed by the mapper transport.

The metadata directory 275 and content mapper 220 collectively form thecontent directory 205. The metadata directory 275 translates a path andfilename to a UUID when originally storing a content object. To find outa UUID or brick addresses, the path and filename is sent to the contentmapper 220, by multicasting using multiple unicast channels to some orall the lookup listeners 328. The namespace is divided between thelookup listeners 328 in addition to having multiple alternative lookuplisteners 328. Multiple lookup listeners 328 that receive the requestwill respond, but the requester only uses the first lookup listener 328to respond. Where there are multiple lookup listeners distributed aroundthe CDN, a distributed database protocol is used to keep all of themreconciled.

The mapper cabinet 324 stores the UUID and brick names or addresses foreach path and filename combination. The lookup listener 328 queries themapper cabinet 324 with the path and filename, to get the UUID for thatpath and filename that is returned with all the brick names that holdthe content file. The lookup listener 328 with the answer passes theUUID and brick information back to the mapper transport 245. Where thereare multiple bricks 130 with the UUID, the mapper transport 245 choosesone and confirms it is there. Additional, bricks 130 could be queried ifunsuccessful. The mapper transport 245 proxies the content object backto the requesting legacy edge cache 304 or legacy edge host 316, butother embodiments could redirect the request directly to the brick 130.

With reference to FIG. 3B, a block diagram of another embodiment thatshows portions of a CMA. This embodiment uses edge caches 305 and edgehosts 315 that support the CMA. Where the content object is not foundlocally, the edge server 230 will request the path and file from thecontent mapper 220. Through multicast to the lookup listeners 328, onewith the answer returns it after a query to its respective mappercabinet 324. The edge server 230 can make an educated guess on whatlookup listeners 328 are likely to respond first instead of querying allof them within the CDN each time. The guess could be based upon whichreturned answers quickly in the past or based upon an estimate of theclosest ones in a network sense.

The UUID and brick names or addresses are returned by the content mapper220 to the edge server 230. The edge cache 305 or edge host 315 candirectly request the content object from a brick address by providing itthe UUID. Where there are multiple bricks with the content object, theycould be queried according to different schemes, for example, queryingin parallel or sequentially. The bricks 130 may be inside or outside theCDN 110. Where a name of a brick is returned instead of an address, adomain name lookup service could be used to find the address.

Referring next to FIG. 4A, a block diagram of an embodiment of a contentbrick 130 is shown. A brick 130 is connected to the switching fabric 240in some way to be managed the CMA. The brick daemon 404 is a softwarelayer that is between the switching fabric 240 and the native fileinterface 408 to translate communication with the CMA to allow storageon the native storage 412. Since there are many native file interfacesand host platforms, the brick daemon 404 is customized for the hostplatform. This embodiment of the brick daemon 404 only does translation,but other embodiments could perform authentication and/or encryption.Files are stored on the native storage 412 with the UUID as the filename.

Referring next to FIG. 4B, a block diagram of an embodiment of aresource 134 is shown. The resource 134 could be any hardware orsoftware that processes a content object. A resource API 405 receivesmutators and other commands. The resource API 405 interfaces with anative resource interface 409 to command a native resource 413 toperform processing on a content object. In some cases, the resource 134has a native API the is suitable for integration with the CMA withoutthe need for a resource API layer.

With reference to FIG. 5, a block diagram of an embodiment of the PRS260 interacting with a metadata directory 275 is shown. The PRS 260includes a policy manager 504 that controls a policy compiler, a policystore 520, and a policy mapping store 518. The policy compiler 528performs disambiguation to resolve conflicts when multiple policiesapply to the same content object. Conflicts can be resolved by ahierarchical scheme where policies higher in the hierarchy takeprecedence. In another embodiment, the policy compiler chooses the mostor least stringent of the conflicting policies. For example, a policythat requires all JPEG files be deleted after two weeks and anotherpolicy that requires all files to be deleted when not requested for aday could be resolved either most stringently to delete the JPEG fileafter not being used for a day or least stringently to be deleted aftertwo weeks. Additionally, any syntax errors in the policies are found andidentified by the policy compiler 528.

The policy store 520 holds all the policies in the CMA. The policies areapplicable to many customers and each have various levels of alterationsfor a particular customer. There are policies for ingest, replication,hosting, transcoding, encryption, compression, thumbnailing, variousworkflows, aging content in/out of system, and other processing for acontent object. Each policy is a function with defined with PRSparameters that include criteria, variables, storage disposition andoptional mutators. Table I below shows examples of some policies withthe PRS parameters that implement the policy and the variables used. Forexample, a transcode policy retrieves a source URL and places it in anintake subdirectory for the transcoder. The transcoder performs anynumber of different transcodes on the source files as specified andstores the resulting files as the specified transcode URLs.

TABLE I Example Ingest and Hosting Policies Policy PRS ParametersVariable(s) Ingest Ingest API Origin URL, Content Tags, InformationTranscode Options, Storage Options, Purge Date Transcoder TranscodeOptions, URL, Format(s) Content Tags Store File(s) File Name, StorageOptions Automatic Purging Purge Date Replication File Copy Number ofCopies, Content Tags, Infrastructure Tags Transcode Retrieve SourceSource URL n Transcodes Transcode Options, Different Transcodes, SourceURL, Content Tags Store Results Transcode URLs Host Hosting API OriginURL, Content Metadata, Information Customer Metadata, Storage Options,Purge Date Store File(s) Stored URL, Storage Options File Aging PurgeDate

Policies are preformulated or custom designed by content providers orcontent receivers. The policy could be in any format (e.g., XML, text,etc.) and could be command line instructions, run-time executed sourcecode or compiled into object code. Policies can age into or out ofsystem. A PRS parameter acts as an instruction in a CDN-specificprogramming language. A policy can be assigned to an end user whoreceives content, a customer who provides content, a content object, aclass of content objects, a directory, and/or any other tag or metadatademarcation.

Criteria for a policy define its applicability to the content objects inthe CMA. Criteria allow size-based processing, MIME type workflows, orany metadata or tag qualifier before performing the policy. For example,a compression policy could be applied to a particular MIME type storedin a particular POP that has not been requested for some period of time.

Each policy has PRS parameter that defines a disposition for the contentobject to be performed after any processing. The disposition can saywhat type bricks 130 or resources 134 to use. The number of copies ofthe content object to have and what geographic spread to place on thosecopies can also be defined. A deletion date can be defined in the PRSparameter.

A mutator indicates a resource 134 that will process the content object.The API to the resource typically includes the source path and filenamefor content file and any number of variable that affect processing bythe resource 134. The mutators are in the form of a URL in thisembodiment, but other embodiments could use any format. The mutator URLidentifies the address of the resource 134, a source content objectlocation that is being operated upon and a number of variables. Themutator URL can perform conditional actions based upon prior mutatorsand/or variables.

The functionality of a policy is demonstrated with an examplethumbnailing policy that uses a thumbnailing resource to createthumbnail images for an image content object. In this example, thepolicy would store any files which end in the file name extension is‘jpg’ in three different locations. One of the locations is in theEuropean Union and two are stored in the United States. Once all copieshave been made, a call to the thumbnailer resource 134 is made, whichgenerates a small thumbnail image of the source JPEG file that is storedin a predetermined location. The thumbnailer resource 134 uses thepathname of the source JPEG file as well as its size in bytes passed asvariables in the mutator URL. The thumbnailer resource 134 is anHTTP-based API which is called with this URI:http://www.imagetransform.org/thumbnailer?path=<full path to sourceimage>&size=<size of image>. The resource is located at the address ofthe imagetransform.org domain, which may or may not be within the CDN110.

In this example, all known bricks 130 have infrastructure tags 508 fortheir geographical locations (e.g., city, metropolitan area, country,supranational entity). For example, a brick 130 in London would betagged with the tags LONDON, UK, EU, and EMEA. A brick in 130 Pariswould be tagged with PARIS, FRANCE, EU, and EMEA. A brick 130 in Chicagowould be tagged CHICAGO, IL, USA, NA, and AMERICAS, and so on.

The one or more databases or data structures hold the infrastructuretags and tagsets 508 and addresses of all bricks 130 or resources 134that comply with each tag or tagset. The tagset could be named to be thesame as the tag, by convention, i.e., LONDON, USA, etc. Tagsets could beconjunctions of two or more tags. For example, a tagset calledLOND-HPERF could contain both the LONDON and HIGH-PERFORMANCE tags. Aquery to the metadata service 524 for a given tag or tagset would returnall bricks 130 and resources 134 that have the tag(s).

All known bricks 130 or other resources 134 are arbitrarily grouped witha tagset having any number of tags. For geographic tags, a brick 130cannot be in London and somewhere else at the same time, so generally ageographic tag are not conjoined with other geographic tags in a tagset.Not all the tags which exist need to be in a tagset—some might bereserved for future use. Similarly, not all tagsets need be utilized inany policy.

This example policy is expressed in a pseudo language below as four PRSparameters. The first PRS parameter is the policy name. For the secondPRS parameter, one or more criteria can be specified as positive ornegative logic to test for a condition before applying the policy. Inthis example, the criteria defines applicability to content files of theJPG MIME type. The disposition in the third PRS parameter is the storageconditions specifying tags and the minimum number of copies.

Policy: “ExamplePol”

Criteria: [{name=‘.*.jpg$’}]

Disposition: [{Tagset=“USA”, MinBricks=2}, {Tagset=“EU”, MinBricks=1}]

ThumbnailMutator=[http://www.imagetransform.org/thumbnailer?path=%p&size=%s]

In order to decide the applicability of this policy, the PRS 260 wouldfirst would look at the name extension of the file as a criteria. If itmatches the regular expression ‘.*.jpg$’ (that is, it ends with the text‘jpg’), then this policy applies. Any other files would not be deemed tobe covered by this policy.

When executing the policy, the PRS 260 would select two bricks whichhave all the tags in the tagset USA, and one brick from the set whichhave all the tags in tagset EU. The bricks could be chosen by anycriteria such as randomly, round robin, available space, cost ofstorage, proximity in network terms, bandwidth cost to transport thefile, etc. Once three receipts come back from those bricks markedCOMPLETE, the source JPEG file itself goes into the COMPLETE state, andthe thumbnail mutator in the PRS parameter list gets called,substituting the metavariables % p with the full path to the object, and% s with the size in bytes of the image object. Other policies couldhave any number of mutators for storage, transcoding, replication, orother processing for a file or asset.

The policy mapping store 518 records which policies are mapped tovarious levels of the hierarchy. Various embodiments could map policiesto the national jurisdiction, regional jurisdiction, CDN-wide,POP-applicable, customer, sub-customer, directory, sub-directory,MIME-type, individual file, etc. to achieve any level of granularity.FIGS. 12A, 12B and 12C, show embodiments of a different policyprioritization hierarchies 1200. Each block represents a level in thehierarchy and can have a number of policies assigned to it. The policiesfor a particular level can be organized in a priority as between theothers at that level. Policies in a higher block take precedence overthose in a lower block during the disambiguation processes performed bythe policy compiler 528. The present embodiment only has two levels inthe hierarchy as illustrated in FIG. 12A. Some policies disassociatethemselves with a particular level of the hierarchy once performed. Forexample, a policy could be used to update coding on the content libraryfrom a legacy format where all new content is received in the updatedcoding. After running the policy once, it can be disassociated from thecustomer with a PRS parameter in the policy that removes the associationin the policy mapping store 518.

The directory structure 532 for this example is illustrated in FIG. 6where each customer has a directory with optional subdirectories. Eachdirectory or subdirectory can hold file names 604 for content objects ofthe customer. The directory structure 532 is stored in the metadatadirectory 275 in this embodiment. Table II shows an example of a portionof the policy mapping 518 for the hierarchy in FIG. 12A and thedirectory structure of FIG. 6. The /ZBS_Radio client has subdirectoriesfor /streams and /podcasts. All the files in the /ZBS_Radio/streams pathhas both ingest and host policies that are applied, while all the filesin the /ZBS_Radio/podcasts path has ingest, transcode and host policiesthat are applied.

TABLE II Policy Mapping Directory Subdirectory File Policy ABS Movie — —Ingest, Replication, Channel Host . . . . . . . . . . . . ZBS RadioStreams — Ingest, Host Podcasts — Ingest, Transcode, Host Realure —Silverthorne Ingest, Replication eBooks Trails.epub Keystone Ingest,Replication Boarding.epub Aventneer.epub Ingest Aventneer Ingest,Replication, Audio.mp3 Transcode

A UUID generator 532 assigns a 256 bit code to each path and filenamestored in the CMA. The UUID becomes the file name for content objectsstored with the various bricks 130 associate with the CMA. The UUID is aone-way function in that the path and file name cannot be determinedfrom the UUID alone, but a query to the mapper cabinet 324 can give thebricks storing a particular UUID and the path and file name.

The metadata directory 275 maintains metadata, tags and tagsets that areused by the policies to process content objects. There is customermetadata 516 describing details about the customer. The customermetadata 516 is entered when the customer configures their account withthe CDN and includes account holding personal information, account, anysub-account(s), zone, channel, confidentiality level, etc. The directoryand subdirectory structure for a customer is stored in the directorystructure 532 in this embodiment, but could be stored with othercustomer metadata 516 in other embodiments.

Also stored is user metadata 540 that is discerned about the end user128. Typically, the end user 128 does not intentionally interface withthe CDN 110 so the user metadata 540 is largely discerned indirectly.Metadata includes usage habits, content preferences, demographicinformation, user identifier, POP location receiving request, and enduser system location. The content player, IP address, cookies or othertechniques may be used to discern one user from another. Privacyconcerns can limit the availability of user metadata 540.

Infrastructure tags and tagsets 508 are assigned to bricks 130 andresources 134. The number of tags increase as customers want greatergranularity in applying policies. Infrastructure tags include: carbonuse, energy use, storage type (e.g., solid state, magnetic, optical,spinning, tape), equipment manufacturer, reliability (e.g.,dual-location replication, RAID level, tape archive), write only, writeonce, interface speed (e.g., SATA, SAS, Ethernet, 10 Gb), retrievallatency, storage cost, physical security surrounding equipment,geographical location of content, various performance discriminators,equipment location to city, region, or country, POP, IPV4 or IPV6compatibility, CDN hosted, user hosted, level of QoS. The tags can beapplied to bricks and resources regardless of them being inside oroutside the CDN 110.

Content metadata 512 relates to content objects with the CMA. Thecontent metadata 512 can additionally be stored in the content objectitself and/or its file name. The content metadata includes MIME type,encoding, container format, copyright terms, cost terms, copyright year,actors, director, studio, program summary, content rating, criticalreview ranking, title, transcript, ad insertion locations, encryption,request popularity, etc. Some content metadata 512 is not stored in thedatabase or store, but is discerned through interaction with the contentfile. For example, MIME type is readily discernable from the file itselfwithout refereeing the content metadata 512 in the store or database.

Bricks 130 and resources 134 are expressly enrolled to work with theCMA. A registration interface 536 is used to enter the address or domainname for the brick 130 or resource 134 that is stored in abrick/resource information store 544. The bricks 130 and resources 134periodically report health and status information through a reportinterface 548 that is also stored in the brick/resource informationstore 544. The metadata directory 275 can periodically request statusand health information using the report interface 548 or can test thebrick 130 or resource 134. Where calls to the brick 130 or resource 134fail or perform poorly, the brick/resource information 544 can beupdated to reflect status.

With reference to FIG. 7, a swim diagram of an embodiment of a processfor using the CMA to retrieve a content object with a legacy edge server235 is shown. The depicted portion of the process begins in block 704where the end user system 102 requests a file from an the legacy edgeserver 235. Where the legacy edge server 235 cannot fulfill the request,the file is requested from the mapper transport 245 in block 708. Therequest from the legacy edge server 235 is typically a URL which isconverted by the mapper transport 245 in block 712. A multicast query ismade to the lookup listeners 328 in block 714 that is received in block716. To achieve parallel requests to the lookup listeners 328, multipleunicast requests are made overlapping in time.

In block 724, a query is made from the lookup listener 328 to the mappercabinet 324. The first lookup listener 328 to find the result in itsrespective mapper cabinet 324, responds to the mapper transport 245 withthe brick addresses and UUID in block 728 that receives them in block734. The mapper transport 245 determines which of the brick addresses touse where there are multiple ones in block 748. The determination can berandom or according to some other scheme. The UUID is requested from theaddress of the selected brick in block 752. If unsuccessful asdetermined in block 756, another address is attempted by looping back toblock 748.

Where the file with the UUID for the name is found on the brick 130, thefile is renamed and sent to the legacy edge server 235 in block 760. Thefile is received in block 764 and returned to the end user system 102 inblock 768. In this way, the CMA is used like an origin server by anylegacy process with the mapper transport 245 translating theinteraction.

Referring next to FIG. 8, a swim diagram of another embodiment of aprocess for using the CMA to retrieve a content object is shown. Thisconfiguration does not use the mapper transport 245 as the edge server230 knows how to interact with the content directory 205 directly. Inblock 804, a request for a file is made by the end user system 102 tothe edge server 230. The path and filename is requested using multicastto the lookup listeners 328, where the content object is not found onthe edge server 230 in block 814. The content directory 205 receives therequest in block 816, determines or looks-up the UUID in block 820 andthe brick names in block 824 from the mapper cabinet 324 to respondfirst with the answer.

The brick addresses and UUID are sent by the content directory 205 inblock 828 and received by the edge server 230 in block 834. The edgeserver 230 determines which brick address to try first in block 848before requesting that UUID from the brick 130 in block 852. If notfound in block 856, another brick address is attempted by looping backto block 848. Where the file is found in block 856, it is renamed andreturned to the end user system 102 in block 868.

With reference to FIG. 9, a flowchart of an embodiment of a process 900for applying policies to a content object is shown. The depicted portionof the process begins in block 904, where the customer account, servicesand policies are configured, which is explained in greater detail inrelation to FIG. 10 below. In block 908, a content object file isreceived from the customer using a landing pad 210, 215 or other API.Some embodiments can add content object files when requested from theCDN 110 and are located after a cache miss. Other embodiments candesignate a path that is automatically reconciled with the CDN 110 usinga policy.

Some policies are triggered by an action such as intake, user request,or other action that would affect the content object file. Otherpolicies are run periodically or according to a schedule, for example,checking a directory for newly encoded files and moving the file backout to the origin server 112 of the content originator 106. In anyevent, the potential policies are determined in block 912, which isexplained in greater detail in relation to FIG. 11. The policiesgenerally applicable to the content file is determined by analysis ofall policies associated with the hierarchy 1200 in block 916. Wherethere are more than one policy, a disambiguation process is performed bythe policy compiler 528 to find the policy that has the highestpriority.

In block 920, the policy is interpreted and performed. The policy isrepresented as a number of PRS parameters that are interpreted toperform some processing on the content object file. The functionality ofblock 920 is explained in greater detail in relation to FIG. 13 below.If there are more policies applicable to the content object file thatare still waiting to complete as determined in block 922, processingloops back to block 912. The just performed policy may have changed thecontent object file such that it qualifies for more or less policies sothat is reanalyzed in block 912. At some point, it is determined block922 that all policies have been performed and the normal operation ofthe CDN 110 utilizes the content object file in its processed form isperformed in block 924.

Upon changes to user, customer or content metadata 540, 516, 512referenced in the applicable policies or tags 508 associate with where acontent object file is stored, the policies are run again. For eachcontent object, the relevant input metadata 512, 516, 540 or tags 508used in the policies are tracked. Where there are changes to any of themetadata 512, 516, 540, tags 508 or policies as determined in block 928,processing loops back to block 912 to rerun the policies.

Referring next to FIG. 10, a flowchart of an embodiment of a process 904for configuring a customer account is shown. The depicted portion of theprocess begins in block 1004 where the customer connects to the CDN 110and authenticates their identity. Certain demographic and paymentoptions may be entered along with customer metadata 516. In block 1008,a landing pad 210 is selected and customized. A landing pad 210 is aningest point and can be configured in any number of ways to efficientlyprovide content objects to the CDN 110.

In block 1012, the customer can choose the number of POPs and/or theirlocation that will host the landing pad. The customer can select thateach POP would have an instantiated landing pad 210 or instantiate oneupon request. To provide for high volume accounts, there can be a numberof landing pads per POP that even scales up or down with demand. Thecustomer can design the directory structure 532 for their account byrenaming directories and adding sub-directories nested down any numberof levels in block 1016.

The customer can customize policy templates, design new policies ormodify their existing policies in block 1020. The policies are mapped tothe hierarchy 1200 in block 1022. Where there are multiple policies fora particular level in the hierarchy, they are put in order of importanceto allow resolving potential conflicts during disambiguation. In block1024, the landing pads 210 start normal operation at the selected POP(s)120. The directory structure and loaded files for the customer can beviewed and modified through the landing pad in block 1028.

With reference to FIG. 11, a flowchart of an embodiment of a process 912for disambiguation of policies is shown. The process 912 is bestunderstood in reference to one hierarchy from FIG. 12A, 12B or 12C. Thedepicted portion of the process 912 begins in block 1104 where allpolicies possibly applicable to the file are found throughout thehierarchy. The policies are all prioritized in block 1108. The tags,metadata and criteria of the PRS parameters in the policies are gatheredin block 1112. Criteria can and other filters in the policies can makemany policies irrelevant to a particular content file.

In block 1116, the inapplicable and conflicting policies are removedfrom the list. Each policy has a criteria that may make the policyinapplicable to the file. Additionally, there can be conflictingpolicies where the lower priority policy is removed. The policy compiler528 also checks for syntax errors or other problems in block 1120. Theinvalid policies are removed from the list in block 1124. The list ofpotential policies are known at the point so that the highest prioritycan be executed.

With reference to FIG. 13, a flowchart of an embodiment of a process 920for performing a policy is shown. The depicted portion of the processbegins in block 1302 where the policy compiler 528 checks the policy forerrors prior to running the policy after being loaded by the policymanager 504. The policy manager 504 checks the policy for any criteriaidentified in a PRS parameter. Where there is a criteria, adetermination is made in block 1308 to see if the criteria is satisfiedto allow further evaluation of the policy. Should the criteria excludefurther processing, processing passes from block 1308 to block 1312where processing of the policy is complete.

Should the policy criteria be satisfied in block 1308, processingcontinues to 1316 to see if there is a mutator PRS parameter in thepolicy. Where there is no mutator, processing goes to block 1344 wherethe content object a disposition PRS parameter defines how the resultingcontent object is stored. The storage may be dependent on variables,metadata and/or tags. The metadata directory 275 can be queried forbricks 130 that comply with a given tag that can be specified in thedisposition PRS parameter to find the one or more bricks 130 to use. Forexample, the disposition could be to store the content object in threelocations with a USA tag. A query would be made to the metadatadirectory 275 and it would choose three from all the bricks 130 with theUSA tag and specify those bricks 130. The policy manager 504 would writethe content object to the addresses specified by the metadata directory275. Where there is one or more mutators as determined in block 1316,processing continues to block 1320.

In block 1320, the address of the resource is parsed from the mutatorURL. Where the address is a domain name, that is resolved to an IPaddress using a domain name service (DNS). The resource 134 API uses aURL in this embodiment so that requesting the URL in block 1324 passesthe source file location and other embedded variables. In someembodiments, the mutator specifies a group of resources that comply witha tag. The metadata directory 275 is queried to choose from the group ofresources with the tag and return the address of the particular resourceto use. For example, the mutator may specify using a transcoder servicein Russia. The metadata directory would find all transcoder serviceswith a Russia tag and return one. The one chosen could be random, roundrobin, based upon loading status from the resource information database544 or some other algorithm.

The resource 134 parses the source file location from the URL in block1328. The content object is retrieved by the resource 134 in block 1332.In block 1336, the resource 134 performs the requested processingaccording to any other variables passed in the URL or other API. Ifthere is another mutator in the policy as determined in block 1340processing loops back to block 1320 for processing. Where it isdetermined in block 1340 that there are no additional mutators in thepolicy, processing goes to block 1344 for execution of the dispositionPRS parameter. In this way, a policy is performed to process a contentobject file.

Referring next to FIG. 14, a flowchart of an embodiment of a process1400 for enrolling a resource 134 or brick 130 into the CMA is shown.The metadata directory 275 knows addresses for the enrolled resources134 and bricks 130 along with the infrastructure tags 508 associate witheach. The depicted portion of the process 1400 begins in block 1404where a new resource 134 or brick 130 is identified for inclusion in theCMA. A unique identifier or name or an address is assigned to theresource 134 or brick 130 in block 1408. The address can be a virtualone that is resolved through DNS. Infrastructure tags for the newenrollee are entered into the CMA in block 1412.

The resource 134 or brick 130 is added to the tag or tagset groups inblock 1416. A query for a tag or tagset can quickly return all theaddresses for resources 134 or bricks 130 by arranging those groupsbeforehand. The resource is added to the CMA by being coupled to theswitching fabric 240 even though it may be inside or outside the CDN110. Periodically, when polled or according to a schedule, the resource134 or brick 130 reports health and other status to the metadatadirectory 275 in block 1424 for retention in the resource informationstore 544. The metadata directory 275 can avoid assigning new contentobjects to a resource 134 or brick 130 that is less healthy or moreoverloaded than the other members in the tag or tagset group.

With reference to FIG. 15, a flowchart of an embodiment of a process1500 for delivering a content object using the CMA is shown. Thedepicted portion of the process begins in block 1504 where the end usersystem 102 queries for content from the CDN 110. Through Anycast,redirection, switching, or DNS resolution, the request finds its way toa ‘nearby’ POP 120. Closeness is a function of network proximity whichgenerally corresponds to geographic proximity, but not necessarily so.

In block 1512, a caching or hosting edge server 230 is assigned. Wherethe edge server 230 cannot satisfy the request locally, a request ismade to the CMA for the content object. Through the process outlined inFIGS. 7 and 8 above, the resource 134 or brick 130 is located and thecontent is relayed or proxied to the edge server 230 in block 1520. Inblock 1524, the edge server fulfils the request. The end user plays thecontent in block 1528.

Referring next to FIG. 16A, a flowchart of an embodiment of a process1600-1 for elastically managing propagation of content objects is shown.This workflow is implemented with the CMA using various policies toscale-up or scale-down the propagation of content objects in a fluidmanner. The depicted portion of the process 1600 begins in block 1604where a policy measures popularity content metadata 512 for a contentobject. A counter in the CDN tracks the popular content and updates thecontent metadata 512 in the metadata directory 275 accordingly.Popularity could be measured on a scale of one to one hundred with themost popular being at one hundred and the least popular being at one.The policy measures acceleration in popularity by keeping a number ofpast data points for the content objects.

In block 1608, the quickest changes are addressed by adding the name ofthe content file to a list in a policy. The footprint algorithm could berun separately in each POP 120 to measure local popularity or could berun to measure popularity in all POPs 120. The footprint is a functionof how many requests are likely, the size of the content object, the QoSdesired for delivery, and the level of CDN service ordered by thecustomer. In block 1612, the policy is passed variables that managepropagation of the content objects to accomplish a desired footprint.The variables would updates a disposition PRS parameter accordingly inthe policy.

In block 1616, the policy implementing the footprint change for thecontent objects experiencing the quickest changes is performed by thepolicy manager 504. The bricks 130 to store or delete in each tag ortagset group are determined in block 1620. The tag and tagsets chosen ascriteria define the footprint even though the metadata directory 275chooses the individual bricks 130 that have the tag or tagset assignedto it. The policy adds or deletes copies of the content objects with thehighest acceleration accordingly.

Referring next to FIG. 16B, a flowchart of an embodiment of a process1600-1 for elastically managing propagation of content objects is shown.Unlike the embodiment of FIG. 16A, this embodiment measures the velocityas a function of the popularity metadata. When the velocity changes, apolicy triggers a reevaluation of the footprint in block 1603. Thevelocity may have to change by a certain percentage before triggeringthe reevaluation or may be checked periodically. Other embodiments couldmeasure poor QoS feedback from end user systems 102 or complaints beforemodifying the footprint in block 1608. When the footprint changes,processing continues through the remainder of the blocks in a mannersimilar to FIG. 16A.

With reference to FIG. 17, a flowchart of an embodiment of a process1700 for using policies to change the jurisdiction used to process acontent object is shown. The POP 120 where the content object lands canbe different from where it is processed and stored. Policies are used toaccomplish customized processing for the different movements of a sourcefile and its various processed versions. Resources 134 or bricks 130 maybe less costly or underutilized in different parts of the CDN 110. Forexample, transcoder resources in India could be underused in the middleof the day in the United States due to the time differences. A policycould move transcodes to resources 134 in India.

The depicted portion of the process 1700 begins in block 1704 where thecustomer manually or automatically provides the content object to alanding pad 210 in one jurisdiction. A jurisdiction could be any legal,geographical or political boundary in this embodiment. The demarcationsof a jurisdiction can be a custom geography perhaps defined in a licenseor other agreement. It is determined in block 1708 that a jurisdictionalpolicy is active and applicable to the content object. In block 1712,the jurisdictional domain to perform the processing defined in thepolicy is determined. The processing could be a resource 134 and/or abrick 130. The content object is sent to brick 130 and/or resource 134in target jurisdictional zone or domain. In block 1720, the contentobject is processed in the chosen jurisdictional zone 1720.

In block 1724, the disposition PRS parameter defining how to store thecontent object is analyzed. The jurisdictional zone for storage of theprocessed file can be different from the jurisdictional zone thatreceived the file and processed the file. Bricks 130 with the propertags or tagsets of the jurisdictional zone are selected from to assignindividual bricks 130. In other examples, the policy may require thatcertain files be processed in the same jurisdictional zone as received.Further, embodiments may require receipt, processing and storage to bein the same jurisdictional zone. Without a policy restricting movement,processing and storage could choose resources and bricks outside thejurisdictional zone based upon, for example, those resources and bricksbeing under utilized.

A number of variations and modifications of the disclosed embodimentscan also be used. For example, the above embodiments have a particulararrangement of the CMA, but blocks could be combined or split in anymanner to still achieve the same functionality. Additionally, portionsof the CMA could reside outside of the CDN. For example, the PRS,metadata directory, and/or content mapper could be maintained outside ofthe CDN.

Specific details are given in the above description to provide athorough understanding of the embodiments. However, it is understoodthat the embodiments may be practiced without these specific details.For example, circuits may be shown in block diagrams in order not toobscure the embodiments in unnecessary detail. In other instances,well-known circuits, processes, algorithms, structures, and techniquesmay be shown without unnecessary detail in order to avoid obscuring theembodiments.

Implementation of the techniques, blocks, steps and means describedabove may be done in various ways. For example, these techniques,blocks, steps and means may be implemented in hardware, software, or acombination thereof. For a hardware implementation, the processing unitsmay be implemented within one or more application specific integratedcircuits (ASICs), digital signal processors (DSPs), digital signalprocessing devices (DSPDs), programmable logic devices (PLDs), fieldprogrammable gate arrays (FPGAs), processors, controllers,micro-controllers, microprocessors, other electronic units designed toperform the functions described above, and/or a combination thereof.

Also, it is noted that the embodiments may be described as a processwhich is depicted as a flowchart, a flow diagram, a data flow diagram, astructure diagram, or a block diagram. Although a flowchart may describethe operations as a sequential process, many of the operations can beperformed in parallel or concurrently. In addition, the order of theoperations may be re-arranged. A process is terminated when itsoperations are completed, but could have additional steps not includedin the figure. A process may correspond to a method, a function, aprocedure, a subroutine, a subprogram, etc. When a process correspondsto a function, its termination corresponds to a return of the functionto the calling function or the main function.

Furthermore, embodiments may be implemented by hardware, software,scripting languages, firmware, middleware, microcode, hardwaredescription languages, and/or any combination thereof. When implementedin software, firmware, middleware, scripting language, and/or microcode,the program code or code segments to perform the necessary tasks may bestored in a machine readable medium such as a storage medium. A codesegment or machine-executable instruction may represent a procedure, afunction, a subprogram, a program, a routine, a subroutine, a module, asoftware package, a script, a class, or any combination of instructions,data structures, and/or program statements. A code segment may becoupled to another code segment or a hardware circuit by passing and/orreceiving information, data, arguments, parameters, and/or memorycontents. Information, arguments, parameters, data, etc. may be passed,forwarded, or transmitted via any suitable means including memorysharing, message passing, token passing, network transmission, etc.

For a firmware and/or software implementation, the methodologies may beimplemented with modules (e.g., procedures, functions, and so on) thatperform the functions described herein. Any machine-readable mediumtangibly embodying instructions may be used in implementing themethodologies described herein. For example, software codes may bestored in a memory. Memory may be implemented within the processor orexternal to the processor. As used herein the term “memory” refers toany type of long term, short term, volatile, nonvolatile, or otherstorage medium and is not to be limited to any particular type of memoryor number of memories, or type of media upon which memory is stored.

Moreover, as disclosed herein, the term “storage medium” may representone or more memories for storing data, including read only memory (ROM),random access memory (RAM), magnetic RAM, core memory, magnetic diskstorage mediums, optical storage mediums, flash memory devices and/orother machine readable mediums for storing information. The term“machine-readable medium” includes, but is not limited to portable orfixed storage devices, optical storage devices, wireless channels,and/or various other storage mediums capable of storing that contain orcarry instruction(s) and/or data.

While the principles of the disclosure have been described above inconnection with specific apparatuses and methods, it is to be clearlyunderstood that this description is made only by way of example and notas limitation on the scope of the disclosure.

What is claimed is:
 1. A content delivery network (CDN) for storingcontent objects and delivering content objects over a network to a usercomputer, the CDN comprising: a switching fabric to receive and routerequests for content objects from user computers to a particular edgeserver, the requests including a filename; and a plurality of points ofpresence (POPs) distributed geographically, each POP comprising: ametadata directory comprising a unique identifier assigner for assigninga unique identifier to a new content object; a content mapper coupled toa plurality of lookup listeners; and an edge server coupled to theswitching fabric and to the content mapper, wherein the edge server isconfigured to receive a request for a content object from the switchingfabric, the request including a file name and/or a path of the requestedcontent object, and wherein the content mapper is configured to receivethe file name and/or the path from the edge server; translate the filename and/or the path into a corresponding unique identifier, transmit,at least partially overlapping in time, the corresponding uniqueidentifier to each of the lookup listeners, receive informationidentifying a location of a storage device of a plurality of storagedevices storing the requested content object from one or more of thelookup listeners, and request the requested content object from thelocation, and wherein each lookup listener of the plurality of lookuplisteners provides location information for any of a same set of storagedevices that store at least some of a requested content object.
 2. Amethod for sourcing a content object from a content delivery network(CDN) having a plurality of points of presence (POPs) distributedgeographically, the method comprising: receiving the content object forstorage on the CDN; determining, by a first content mapper in a firstPOP of the plurality of POPs, a unique identifier for the content objectto distinguish it from other content objects in the CDN; transmitting,from the first content mapper, the unique identifier to each of theplurality of POPs distributed geographically within the CDN; storing thecontent object on a storage device chosen from a plurality of storagedevices; receiving a uniform resource locator (URL) for the contentobject indicating a file name and path from an end user system at asecond POP of the plurality of POPs; multicasting informationcorresponding to the file name and a path to a plurality of lookuplisteners, wherein each lookup listener provides location informationfor any of a same set of storage devices that store at least some of thecontent object; receiving a response from a lookup listener including afirst location of the storage device and the unique identifier;requesting the unique identifier from the first location; returning atleast some of the content object from the first location to a secondlocation within the CDN; and returning at least some of the contentobject to the end user system from the CDN.
 3. The method for sourcing acontent object from a CDN having a plurality of POPs distributedgeographically as recited in claim 2, wherein the second POP was chosenfrom the plurality of POPs using an Anycast routing scheme.
 4. Themethod for sourcing a content object from a CDN having a plurality ofPOPs distributed geographically as recited in claim 2, wherein thelookup listener was a first of plurality multiple of lookup listeners torespond to the multicasted information.
 5. The method for sourcing acontent object from a CDN having a plurality of POPs distributedgeographically as recited in claim 2, further comprising reconcilinglookup information between the plurality of lookup listeners.
 6. Amethod for sourcing a content object from a content delivery network(CDN) having a plurality of points of presence (POPs) distributedgeographically, the method comprising: receiving the content object forstorage on the CDN; determining, by a content mapper, a uniqueidentifier for the content object to distinguish it from other contentobjects in the CDN; transmitting, from the content mapper, the uniqueidentifier to each of a plurality of content directories distributedgeographically within the CDN; storing the content object on a storagedevice chosen from a plurality of storage devices; receiving a uniformresource locator (URL) for the content object indicating a file name andpath from an end user system at a POP of the plurality of POPs;multicasting information corresponding to the file name and a path tothe plurality of content directories, wherein each content directory canprovide location information for any of a same set of storage devicesthat store at least some of the content object; receiving a responsefrom a content directory including a first location of the storagedevice and the unique identifier; requesting the unique identifier fromthe first location; returning at least some of the content object fromthe first location to a second location within the CDN; and returning atleast some of the content object to the end user system from the CDN. 7.The method for sourcing a content object from a content delivery network(CDN) having a plurality of points presence (POPs) distributedgeographically of claim 6, wherein the determining the unique identifieris a one-way algorithm such that nothing can be learned about the path,the file name or the content object from the unique identifier alone. 8.The method for sourcing a content object from a CDN having a pluralityof POPs distributed geographically as recited in claim 6, wherein themulticasting includes initiating a plurality of unicast streams,coextensive in time, to send the information.
 9. The method for sourcinga content object from a CDN having a plurality of POPs distributedgeographically as recited in claim 6, wherein the POP was chosen fromthe plurality of POPs using an Anycast routing scheme.
 10. The methodfor sourcing a content object from a CDN having a plurality of POPsdistributed geographically as recited in claim 6, wherein the contentdirectory was a first of a plurality of content directories to respondto the multicasted information.
 11. The method for sourcing a contentobject from a CDN having a plurality of POPs distributed geographicallyas recited in claim 6, further comprising reconciling lookup informationbetween the plurality of content directories.
 12. The method forsourcing a content object from a CDN having a plurality of POPsdistributed geographically as recited in claim 6, further comprising:hashing the content object, the path and/or the file name.
 13. A methodfor sourcing a content object from a content delivery network (CDN)having a plurality of points of presence (POPs) distributedgeographically, the method comprising: receiving the content object forstorage on the CDN; associating, by a first content mapper in a firstPOP of the plurality of POPs, the content object with an identifier todistinguish it from other content objects in the CDN; transmitting, fromthe first content mapper, the identifier to each of the plurality ofPOPs distributed geographically within the CDN; storing the contentobject on a first storage device chosen from a plurality of storagedevices; receiving a first request for the content object from an enduser system at a second POP of the plurality of POPs; transmitting, atleast partially overlapping in time, information about the requestedcontent object to a plurality of lookup listeners, wherein each lookuplistener provides location information for any of the plurality a sameset of storage devices that store at least some of the content object;receiving a response from a first lookup listener indicating that thecontent object is stored at a first location, the first location being alocation of the first storage device; transmitting, to the firstlocation, a second request for the content object; receiving, at asecond location within the CDN, at least some of the content object fromthe first location, the second location being different from the firstlocation; and returning at least some of the content object to the enduser system from the CDN.
 14. The method for sourcing a content objectfrom the CDN having the plurality of points of presence (POPs)distributed geographically as recited in claim 13, further comprising:receiving a response from a second lookup listener indicating that thecontent object is stored at a third location, the third location being alocation of a second storage device, and determining that the responsefrom the first lookup listener was received after the response from thesecond lookup listener.
 15. The method for sourcing a content objectfrom the CDN having the plurality of POPs distributed geographically asrecited in claim 13, wherein the second request for the content objectis transmitted immediately and automatically after receiving theresponse from the first lookup listener.
 16. The method for sourcing acontent object from the CDN having the plurality of POPs distributedgeographically as recited in claim 13, wherein the information comprisesthe identifier.
 17. A content delivery network (CDN) having a pluralityof points of presence (POPs) distributed geographically for sourcing acontent object, the CDN comprising two or more hardware serversprogrammed for: receiving the content object for storage on the CDN;determining, by a first content mapper in a first POP of the pluralityof POPs, a unique identifier for the content object to distinguish itfrom other content objects in the CDN; transmitting, from the firstcontent mapper the unique identifier to each of the plurality of POPsdistributed geographically within the CDN; storing the content object ona storage device chosen from a plurality of storage devices; receiving auniform resource locator (URL) for the content object indicating a filename and a path from an end user system at a POP of the plurality ofPOPs; multicasting information corresponding to the file name and thepath to a plurality of lookup listeners, wherein each lookup listenerprovides location information for any of the plurality of storagedevices that store at least some of the content object; receiving aresponse from a lookup listener including a first location of thestorage device and the unique identifier; requesting the uniqueidentifier from the first location; returning at least some of thecontent object from the first location to a second location within theCDN; and returning at least some of the content object to the end usersystem from the CDN.
 18. The CDN having the plurality of POPsdistributed geographically for sourcing the content object as recited inclaim 17, wherein the second location is an edge server in the POP. 19.The CDN having the plurality of POPs distributed geographically forsourcing the content object as recited in claim 17, wherein the firstlocation is accessed using an internet protocol (IP) address.
 20. TheCDN having the plurality of POPs distributed geographically for sourcingthe content object as recited in claim 17, wherein the storage device isunaware of the file name and/or the path.
 21. A content delivery network(CDN) having a plurality of points of presence (POPs) distributedgeographically for sourcing a content object, the CDN comprising: amapper transport, located in a first POP of the plurality of POPs for:receiving a request for a content file; and transmitting, at leastpartially overlapping in time, multiple and identical requests forinformation about a location of the content file to each of a pluralityof lookup listeners, distributed geographically within the CDN; and afirst of a plurality of lookup listeners programmed for: receiving oneof the location requests; querying a mapper cabinet that associatescontent files with storage addresses; and transmitting informationidentifying a storage location of the content file to the mappertransport, wherein each lookup listener of the plurality of lookuplisteners provides location information for any of a same set-of storagedevices that store at least some of the content file.
 22. The CDN havinga plurality of POPs distributed geographically for sourcing the contentobject as recited in claim 21, wherein the mapper transport is furtherprogrammed for requesting the content file from the storage location.23. The CDN having a plurality of POPs distributed geographically forsourcing the content object as recited in claim 21, wherein thetransmitted requests include a unique identifier assigned to the contentfile.
 24. The CDN having a plurality of POPs distributed geographicallyfor sourcing the content object as recited in claim 21, wherein thestorage location is outside a domain of the CDN.